Fluorocarbons have been used in the treatment of paper to produce oil and grease resistant (OGR) grades of paper for a wide range of applications including packaging for fast food, microwave popcorn, and bakery goods. However, various governmental agencies are mandating restrictions on the use of fluorocarbons, thereby requiring an alternative barrier material. One of the challenges for alternatives to fluorocarbons is maintenance of the low blocking properties inherent in these fluorocarbons without decreasing barrier performance.
WO 2009/142739 teaches a paper coating composition with a crosslinking agent such as zinc or zirconium and at least 2 weight percent of a high aspect ratio exfoliated nanofiller. The inclusion of this nanofiller particles is described as being critical to improvements to oil, grease, and block resistance; nevertheless, the presence of nanofillers can be deleterious for packaging applications that require creasing or folding.
Accordingly, it would be an advance in the art of paper coatings to find an environmentally acceptable alternative to formulations that include fluorocarbons or formulations requiring high aspect ratio nanofillers to achieve oil, grease, and block resistance.